| Ridderkerk to Oberkirch | 277.02 mi (445.82 km) |
| Ridderkerk to Obernburg am Main | 242.52 mi (390.29 km) |
| Ridderkerk to Obernkirchen | 193.84 mi (311.95 km) |
| Ridderkerk to Oberschleissheim | 397.13 mi (639.11 km) |
| Ridderkerk to Oberstdorf | 399.01 mi (642.15 km) |
| Ridderkerk to Obertraubling | 388.50 mi (625.24 km) |
| Ridderkerk to Obertshausen | 222.20 mi (357.60 km) |
| Ridderkerk to Oberursel | 207.48 mi (333.90 km) |
| Ridderkerk to Ochsenfurt | 283.70 mi (456.57 km) |
| Ridderkerk to Ochsenhausen | 353.68 mi (569.20 km) |
| Ridderkerk to Ochtrup | 112.55 mi (181.14 km) |
| Ridderkerk to Odenthal | 122.71 mi (197.48 km) |
| Ridderkerk to Oelde | 151.52 mi (243.85 km) |
| Ridderkerk to Oelsnitz | 342.78 mi (551.65 km) |
| Ridderkerk to Oer-Erkenschwick | 114.43 mi (184.15 km) |
